Feeler and control device

ABSTRACT

A feeler and a control device formed of a nozzle and a reflecting surface or plate determining the presence or absence on body surface within the control area includes a nozzle having an inner passage emitting an inner control jet and an outer passage surrounding the inner passage and terminating in an annular part of substantial length. Gas under pressure is supplied to both the passages. A signal device for measuring the pressure is connected to the inner passages.

United States Patent [72] Inventors HanshelnrlchGlattli 252, Kusnacht; Jan Richard Peter De Fries, Allenmoostrasse 124, Zurich, both of, Switzerland {21 Appl. No. 834,836

[22] Filed June 19, 1969 [4S 1 Patented Aug. 24, 1971 [32] Priority June 20, 1968 33] Germany [54] FEELER AND CONTROL DEVICE 10 China, 3 Drawing Figs.

[52] US. CL 137/815 [51] hit. (I 'Fl5c 4/00 [50] Field Search 137/815; 73/375, 37.6, 37.8

[56] References Cited UNITED STATES PATENTS 2,692,498 10/1954 Knobel 73/375 3,039,490 6/1962 Carlson, Jr. 137/815 3,232,095 2/1966 Syrnrnoski et a1. 137/815 X 3,250,116 5/1966 Hatch, Jr 137/815 X 3,258,023 6/1966 Bowles 137/815 3,272,215 9/1966 Biomsen et a1. 137/815 3,482,433 12/1969 Gladwyn 73/375 3,503,410 3/1970 Richards 137/815 Primary Examiner-Samuel Scott Attorney.lennings Bailey, Jr.

ABSTRACT: A feeler and a control device formed of a nozzle and a reflecting surface or plate determining the presence or absence on body surface within the control area includes a nozzle having an inner passage emitting an inner control jet and an outer passage surrounding the inner passage and terminating in an annular part of substantial length. Gas under pressure is supplied to both the passages. A signal device for measuring the pressure is connected to the inner passages.

INVENTOR HANSHEINRICH GLKFT'L! TAN RICHARD PETER DE FRIES FEELER AN D CONTROL DEVICE The invention refers to a feeler and control device and more particularly to a device of the aforesaid kind consisting of a nozzle and of a reflecting surface or plate and serving to determine and ascertain the presence or absence and eventually also the exact position of a body or a body surface within a control area, said nozzle delivering a control jet directed towards the said reflecting surface or plate.

Known arrangements of comparable kind are operated by means of a photoelectric cell, for instance if they are used as a so-called light barrier with a transmitter on the one side and a receiver on the other side of the area to be controlled. The use of those arrangements, however, is limited; for the first premise for them is that on both sides of the area to be controlled there is space available for receiving the transmitter, respectively the receiver. However, this is not possible in any cases. Moreover, the arrangements in question are not usable for controls, when transparent work pieces or objects pass through the area under control. Therefore, so-called reflex light barriers have been developed for such cases, with which a light beam sent out from a transmitter hits upon the surface of the workpiece, is reflected by it, and is taken up thereupon by a receiver placed on the same side as the transmitter. But these arrangements, too, require v a considerable space, because the transmitter and the receiver must have equal distances from a line that is perpendicular to the surface to be controlled. In addition to that, these said arrangements can not be used with pastelike workpieces and have, moreover, the disadvantage to make it necessary to be attended to, for the capacity of the photoelectric cell in operation must be tested again and again. On the other hand the sensitivity of comparable pneumatic arrangements is not high enough. The purpose of the invention presented now is to remove these handicaps. To this purpose the new device is characterized in that the said control jet is an inner control jet and guided on its way from the said nozzle to the said reflecting plate or surface by means of a tubelike and approximatively cylindrical or conical guide surrounding it and constituted by a hollow cylindrical jet having a ringlike cross section, and wherein, furthermore, the speed of the said hollow cylindrical jet surrounding the said inner control jet is greater than, and approximatively twice as great as, the speed of the said inner control jet, whereby at least the first considerable rise of pressure within the area of the said inner control jet takes place upon the outer hollow cylindrical jet striking the reflecting surface or plate, and whereby the rise in pressure of the said inner control jet is comparable as to steepness and direction to the signal produced normally between the said reflecting surface or plate, and the said nozzle. Thereby, there is provided: an outer jet nozzle connected on its inlet side with a source of pressure medium and serving to deliver the outer hollow cylindrical jet, and an inner jet nozzle arranged concentrically to the said outer jet nozzle and arranged with respect to the control area on the side of the outer jet nozzle, the outlet side of this inner jet nozzle facing the control area and its inlet side being connected with a signal or a signal device. The invention is based on the idea that devices with baffle or reflecting plates or surfaces are especially fit for controlling tasks, but DRAWINGS an all-round application calls for a greater distance between the device and the surface or area to be controlled. A greater distance, however, to the surface in question calls for a contrivance to guide the measuring or controlling jet. An arrangement according to the invention allows to test any kind of workpieces, whether they are magnetic or transparent or pasty; a minimal space is sufficient, because the transmitter and the receiver are coaxially arranged with respect to each other and on the same side of the area to be controlled. The result is a device that is highly sensitivelayers of 0.2 mm. or the like can be made out-and that allows control operations without any direct contact. Service or at tendance is practically unnecessary. The device can be used in dark rooms, with materials that are sensitive to light. it works with minimal pressures so that the consumption of air is trifling, even with greater distances the signals obtained can be utilized, a fact that is due to the extreme sensitiveness of the device. By means of suitably shaping the nozzles a great sensitiveness in axial and lateral direction is obtained so that by a minimal change of the distance between the nozzle and the baffle or reflecting surface or plate a sudden and relatively steep change of pressure of the initial signal is obtained. The fact that the outer jet nozzle surrounds the inner jet nozzle concentrically, above all, and that pressure air flows out of both nozzles, creates a dust-guard protection, by which the inner jet nozzle is protected against dirt and dust. Devices of the type described above are used to count or register workpieces, to indicate the level of a liquid, to control the various operations along an assembly line, to signal any defect in the tooling, etc.

These and other objects, features and advantages of the present invention will become further apparent from the following detailed description thereof, whereby in the drawings several embodiments of the invention are shown.

FlGS. l and 2 show two embodiments of the device presented by the inventors in a sectional side view of the whole device respectively of a part of it.

FIG. 3 illustrates the pressure development in the signal line of the new device as compared with the distance of the baffle or reflecting surface or plate from the jet nozzle.

The device according to the invention has an outer jet nozzle l and an inner jet nozzle 2. The outer jet nozzle which at its inlet side is connected with a source of pressurized air and which serves to deliver a jet or blast of air to the control area or to a baffle or reflecting plate is constructed'as a ring nozzle and surrounds the inner jet nozzle concentrically. This outer jet nozzle ends in a narrow cylindrical and ringlike outlet or passage 10 the feed or supply line 3 for the pressurized air may be connected with it by means of a distributing channel not shown. With the embodiment shown in FIG. 1 of the drawings the outer jet nozzle consists-as seen in flow direction according to arrow 4of an inlet portion 1b having the shape of a first cylindrical ring, of a middle portion 10 having the shape of a conical ring the width or gap of which becomes smaller in direction towards the outlet and, finally, of the already mentioned outlet portion la which has the shape of a second cylindrical ring, the outer diameter and its thickness or width and its gap of which are smaller than the corresponding dimensions of the first cylindrical ring lb, whereas its length corresponds approximatively to five times the breadth or width of the gap. These dimensions lead to an especially favorable steady laminar flow. The inner jet nozzle 2 is concentrically arranged with respect to the surrounding outer jet nozzle 1, whereby both nozzles are arranged on the same side of the control area. The inlet side of the inner jet nozzle is directed towards the area to be controlled, its outlet side is connected with a signal line. Hereby, the inner jet nozzle tapers or diminishes conically from its free end at the inlet side, as is shown at 2a, until it changes into an axial channel 2b of constant diameter that can be connected with the signal line and that is connected at the connection point 14a with the cross channel 14b. The inlet portion 1b of the outer jet nozzle is connected with the channel 2b and the cross channel 14b, respectively, by means of a connecting channel 6 which contains a throttle 5 or throttling portion which with an embodiment not shown in the drawings may have a passage with a cross section that is adjustable from without. This throttle is constituted by a passage with a smaller cross section in a threaded piece 7 that is screwed into a suitable threaded portion 8 of the connecting channel 6. This threaded piece 7 is inserted into the bore 8 which can be closed by means of the screwplug 9. The pressure for the inner jet nozzle is therefore obtained from the supply to the outer hollow jet by throttling.

With the embodiment shown in FIG. 1 of the drawings the device consists of a nozzle containing body 10 containing the outer jet nozzle and the inner jet nozzle and of a connecting body 11 which is assembled to the body 10 to form a unitary block, said connecting body 11 containing the connections for the two nozzles as well as the throttling portion, whereby the nozzle-containing body and the connecting body are axially assembled by inserting suitable packing rings 12a, 12b therebetween. The packing rings surround the nozzle on the outside as well as on the inside. The nozzle containing body consists of two portions 17a, 17b, which are coaxial, whereby the inner portion 170 contains the inner jet nozzle and the outer jet nozzle is enclosed or contained between said two portions.

With the embodiments shown in the drawings the connection 13 for the signal line is laterally branched off the connecting body. However, the connection for the signal line can also be axially branched off the connecting body starting from the frontside end of the connecting body which is turned away from the nozzle panel body, in which case an axial channel has to connect the axial duct coming from the inner jet nozzle with the signal line. The arrangement to be chosen depends on the field of application. In the region of the openings of the nozzles the nozfle containing body is conically diminishing in direction towards its free end, as shown at 18, whereby its outside surface and the longitudinal axis form together an acute angle of 40 maximally, for instance of 25. In this case the whirling is unimportant, the jet or stream is scarcely disturbed, the axial as well as the lateral sensitiveness are especially high.

The unitary block constituted by the nozzle-containing body and the connecting body is surrounded by a protecting sleeve 15 the free end 15a of which axially projects beyond the free ends of the two nozzles l and 2. The signal-amplifying device may also be assembled with the nozzle-containing body and the connecting body to form a constructional unit. The signal line leads to an indicator device working, for instance, electrically, pneumatically or hydraulically.

With the embodiment shown in the drawings the nozzles are exchangeable so that a sufficient radius of influence and a sufficient sensitiveness on the one hand and a minimal consumption on the other hand can be attained and adjusted in a simple way. The throttling portion can be regulated, too, so that in this way the device can be calibrated and adapted and adjusted to various distances and various sensitiveness. As compared to the electric light barrier the new device has the advantage of being usable also in rooms which are not explosionproof, whereby disturbances analogue to those which can not be avoided with ultrasonic devices will not show up. The new device can be used with high ambient temperatures, for instance up to 800, a feeding pressure of 0.050.2 0.2 atu (i.e. 1.2 at.) is sufficient. No attendance or service is necessary. Faulty manipulations can practically do no damage to the new device so that it can be said that the duration of the new device is almost unlimited. The operation of the new device is not influenced negatively by dirt and dust. The device may be used in dark rooms, to control or feel up or scan transparent bodies or objects, to control automatic welding machines or machines that are operated in rooms where explosions may occur and the ambient temperatures are higher than usual. The new device can also be used to control pumps in dependence on the level of the liquid, it can be used for measuring the flow passing therethrough, for reading perforated strips with low frequencies for subdividing strips into predetermined lengths, for comparing and measuring lengths, for counting parts, for controlling packing machines, for controlling cutting and stamping tools, etc. With the arrangement according to FIG. 2 there is arranged within the axial channel coming from the inner jet nozzle, an electric resistance wire 2] in connection with a signal line by means of which a signal is actuated, as soon as the degree of heating of the resistance wire is changed due to the change of the flow speed of the air within the channel 20, which air cools the wire 21. The arrows in FIG. 1 indicate the air flow. It is to be seen that whenever the air coming out of the nozzle 2a at a lower speed than that which comes out of the nozzle la hits against the baffle or reflecting plate, there takes place in the channel 2a back pressure which produces the signal.

The FIG. 3 is a diagram showing the pressure p in relation to the distance g between the nozzle and the baffle or reflecting plate. The sudden change of pressure obtainable by the invention is made visible at 22. With a device according to the invention the arrangement may be also such that the signal line leads to a control element, for instance to a valve via a pressure amplifier.

Although our invention has been illustrated and described with reference to the preferred embodiments thereof we wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed our invention, what we claim is:

1. A feeler and control device comprising a nozzle and a reflecting surface or plate and serving to determine and ascertain the presence or absence and the exact position of a body or a body surface within a control area, said nozzle delivering a control jet directed towards the said reflecting surface or plate, wherein the said nozzle includes an inner passage for emitting an inner control jet and an outer passage for forming an outer jet to guide the inner control jet on its way from the said nozzle to the said reflecting plate or surface, said outer passage being tubular and round in cross section, the outlet portion of said passage comprising an annular part of substantial length, the speed of the said outer jet being greater than the speed of the said inner control jet, whereby at least the first considerably rise of pressure within the area of the said inner control jet takes place upon the outer hollow cylindrical jet striking the reflecting surface or plate, and whereby the rise in pressure of the said inner control jet is comparable as to steepness and direction to the signal produced normally between the said reflecting surface or plate and the said nozzle, the outer passage being connected on its inlet side with a source of pressure medium and serving to deliver the outer jet, and the inner passage being arranged concentrically to the said outer passage and its inlet being connected with a signal means.

2. The device set forth in claim 1, wherein the said inner passage has a first channel portion of constant diameter which is connectable to the signal line and a conical portion enlarging in direction towards the free end on the outlet side.

3. The device set forth in claim 1, wherein the distance between the said nozzle and the said reflecting surface or plate lies within a range between a minimal amount corresponding to a fraction of. the nozzle diameter and a maximal amount corresponding to several times the nozzle diameter.

4. The device set forth in claim 1, wherein the said outer passage is connected with a supply line for the pressure medium through a distributing channel and consists as seen in direction of flow of an inlet portion having the shape of a first cylindrical ring, and of a middle portion having the shape of a conical ring narrowing in direction towards the outlet, the outlet portion having the shape of a second cylindrical ring the outer diameter and the width of which are smaller than the corresponding dimensions of the first cylindrical ring and the length of which in axial direction is about five times greater than its width.

5. The device set forth in claim 4, wherein the said outer passage and the said inner passage are connected by a connection channel containing a throttling portion the cross section of which is adjustable from the outside.

6. The device set forth in claim 5, wherein the said throttling portion is constituted by a narrow passage in a threaded body screwed into a threaded portion of the connecting channel.

7. The device set forth in claim 6, wherein there is provided a nozzle-containing body containing the outer passage and the inner passage and a connecting body containing the connections for the said two passages and for the throttling portion, said passage-containing body and said connecting body being assembled to form a unitary block, said passage-containing body comprising two portions surrounding one another in coaxial arrangement, the inner one of said two portions containing the inner passage and the outer one of the said two portions containing the outer passage.

at most 40. I

10. The device set forth in claim 9, wherein the said unitary block constituted by the said passage-containing body and the said connecting body is surrounded by a protecting sleeve the free end of which projects beyond the free ends of the said two passages as seen in axial direction and which contains several bores distributed uniformly along its circumference. 

1. A feeler and control device comprising a nozzle and a reflecting surface or plate and serving to determine and ascertain the presence or absence and the exact position of a body or a body surface within a control area, said nozzle delivering a control jet directed towards the said reflecting surface or plate, wherein the said nozzle includes an inner passage for emitting an inner control jet and an outer passage for forming an outer jet to guide the inner control jet on its way from the said nozzle to the said reflecting plate or surface, said outer passage being tubular and round in cross section, the outlet portion of said passage comprising an annular part of substantial length, the spEed of the said outer jet being greater than the speed of the said inner control jet, whereby at least the first considerably rise of pressure within the area of the said inner control jet takes place upon the outer hollow cylindrical jet striking the reflecting surface or plate, and whereby the rise in pressure of the said inner control jet is comparable as to steepness and direction to the signal produced normally between the said reflecting surface or plate and the said nozzle, the outer passage being connected on its inlet side with a source of pressure medium and serving to deliver the outer jet, and the inner passage being arranged concentrically to the said outer passage and its inlet being connected with a signal means.
 2. The device set forth in claim 1, wherein the said inner passage has a first channel portion of constant diameter which is connectable to the signal line and a conical portion enlarging in direction towards the free end on the outlet side.
 3. The device set forth in claim 1, wherein the distance between the said nozzle and the said reflecting surface or plate lies within a range between a minimal amount corresponding to a fraction of the nozzle diameter and a maximal amount corresponding to several times the nozzle diameter.
 4. The device set forth in claim 1, wherein the said outer passage is connected with a supply line for the pressure medium through a distributing channel and consists as seen in direction of flow of an inlet portion having the shape of a first cylindrical ring, and of a middle portion having the shape of a conical ring narrowing in direction towards the outlet, the outlet portion having the shape of a second cylindrical ring the outer diameter and the width of which are smaller than the corresponding dimensions of the first cylindrical ring and the length of which in axial direction is about five times greater than its width.
 5. The device set forth in claim 4, wherein the said outer passage and the said inner passage are connected by a connection channel containing a throttling portion the cross section of which is adjustable from the outside.
 6. The device set forth in claim 5, wherein the said throttling portion is constituted by a narrow passage in a threaded body screwed into a threaded portion of the connecting channel.
 7. The device set forth in claim 6, wherein there is provided a nozzle-containing body containing the outer passage and the inner passage and a connecting body containing the connections for the said two passages and for the throttling portion, said passage-containing body and said connecting body being assembled to form a unitary block, said passage-containing body comprising two portions surrounding one another in coaxial arrangement, the inner one of said two portions containing the inner passage and the outer one of the said two portions containing the outer passage.
 8. The device set forth in claim 7, wherein a signal-amplifying device is assembled with the passage-containing body and the connecting body to form a unit.
 9. The device set forth in claim 7, wherein the portion of said passage-containing body corresponding to the outlet openings of the said passages tapers conically so as to narrow in direction towards the free end thereof, its outer peripherical surface enclosing with the longitudinal axis an acute angle of at most 40*.
 10. The device set forth in claim 9, wherein the said unitary block constituted by the said passage-containing body and the said connecting body is surrounded by a protecting sleeve the free end of which projects beyond the free ends of the said two passages as seen in axial direction and which contains several bores distributed uniformly along its circumference. 